cirSIRT5 induces ferroptosis in bladder cancer by forming a ternary complex with SYVN1/PHGDH.

Bladder cancer (BC) represents a prevalent and formidable malignancy necessitating innovative diagnostic and therapeutic strategies. Circular RNAs (circRNAs) have emerged as crucial regulators in cancer biology. In this study, we comprehensively evaluated ferroptosis levels in BC cells utilizing techniques encompassing lipid peroxidation assessment, transmission electron microscopy, and malondialdehyde (MDA) measurement. Additionally, we probed into the mechanistic intricacies by which circRNAs govern BC, employing RNA pull-down, RNA immunoprecipitation (RIP), and immunoprecipitation (IP) assays. Our investigation unveiled circSIRT5, which displayed significant downregulation in BC. Notably, circSIRT5 emerged as a promising prognostic marker, with diminished expression correlating with unfavorable clinical outcomes. Functionally, circSIRT5 was identified as an inhibitor of BC progression both in vitro and in vivo. Mechanistically, circSIRT5 exerted its tumor-suppressive activities through the formation of a ternary complex involving circSIRT5, SYVN1, and PHGDH. This complex enhanced the ubiquitination and subsequent degradation of PHGDH, ultimately promoting ferroptosis in BC cells. This ferroptotic process contributed significantly to the inhibition of tumor growth and metastasis in BC. In addition, FUS was found to accelerate the biogenesis of circSIRT5 in BC. These findings provide valuable insights into the pivotal role of circSIRT5 in BC pathogenesis, underscoring its potential as a diagnostic biomarker and therapeutic target for this malignancy.

Integrating single-cell transcriptomics to reveal the ferroptosis regulators in the tumor microenvironment that contribute to bladder urothelial carcinoma progression and immunotherapy.

Background: Ferroptosis, as a novel form of programmed cell death, plays a crucial role in the occurrence and development of bladder cancer (BCa). However, the regulatory mechanisms of ferroptosis in the tumor microenvironment (TME) of BCa remain to be elucidated. Methods: Based on single-cell RNA (scRNA) transcriptomic data of BCa, we employed non-negative matrix factorization (NMF) dimensionality reduction clustering to identify novel ferroptosis-related cell subtypes within the BCa TME, aiming to explore the biological characteristics of these TME cell subtypes. Subsequently, we conducted survival analysis and univariate Cox regression analysis to explore the prognostic significance of these cell subtypes. We investigated the relationship between specific subtypes and immune infiltration, as well as their implications for immunotherapy. Finally, we discovered a valuable and novel biomarker for BCa, supported by a series of in vitro experiments. Results: We subdivided cancer-associated fibroblasts (CAFs), macrophages, and T cells into 3-5 small subpopulations through NMF and further explored the biological features. We found that ferroptosis played an important role in the BCa TME. Through bulk RNA-seq analysis, we further verified that ferroptosis affected the progression, prognosis, and immunotherapy response of BCa by regulating the TME. Especially ACSL4+CAFs, we found that high-level infiltration of this CAF subtype predicted worse prognosis, more complex immune infiltration, and less response for immunotherapy. Additionally, we found that this type of CAF was associated with cancer cells through the PTN-SDC1 axis, suggesting that SDC1 may be crucial in regulating CAFs in cancer cells. A series of in vitro experiments confirmed these inferences: SDC1 promoted the progression of BCa. Interestingly, we also discovered FTH1+ macrophages, which were closely related to SPP1+ macrophages and may also be involved in the regulation of BCa TME. Conclusion: This study revealed the significant impact of ferroptosis on bladder cancer TME and identified novel ferroptosis-related TME cell subpopulations, ACSL4+CAFs, and important BCa biomarker SDC1.

Machine learning identifies the role of SMAD6 in the prognosis and drug susceptibility in bladder cancer.

BACKGROUND: Bladder cancer (BCa) is among the most prevalent malignant tumors affecting the urinary system. Due to its highly recurrent nature, standard treatments such as surgery often fail to significantly improve patient prognosis. Our research aims to predict prognosis and identify precise therapeutic targets for novel treatment interventions. METHODS: We collected and screened genes related to the TGF-ß signaling pathway and performed unsupervised clustering analysis on TCGA-BLCA samples based on these genes. Our analysis revealed two novel subtypes of bladder cancer with completely different biological characteristics, including immune microenvironment, drug sensitivity, and more. Using machine learning classifiers, we identified SMAD6 as a hub gene contributing to these differences and further investigated the role of SMAD6 in bladder cancer in the single-cell transcriptome data. Additionally, we analyzed the relationship between SMAD6 and immune checkpoint genes. Finally, we performed a series of in vitro assays to verify the function of SMAD6 in bladder cancer cell lines. RESULTS: We have revealed two novel subtypes of bladder cancer, among which C1 exhibits a worse prognosis, lower drug sensitivity, a more complex tumor microenvironment, and a 'colder' immune microenvironment compared to C2. We identified SMAD6 as a key gene responsible for the differences and further explored its impact on the molecular characteristics of bladder cancer. Through in vitro experiments, we found that SMAD6 promoted the prognosis of BCa patients by inhibiting the proliferation and migration of BCa cells. CONCLUSION: Our study reveals two novel subtypes of BCa and identifies SMAD6 as a highly promising therapeutic target.

Identification of a novel ferroptosis-inducing micropeptide in bladder cancer.

Bladder cancer (BC) is a common malignancy in males, and currently lacks ideal therapeutic approaches. Exploring emerging therapeutic targets from the perspective of endogenous peptides to improve the prognosis of bladder cancer patients holds promise. In this study, we have identified CTSGDP-13, a novel endogenous peptide, which demonstrates potential anti-cancer effects in BC. Our findings reveal that CTSGDP-13 can promote ferroptosis in BC cells, both in vitro and in vivo, leading to the inhibition of BC progression. Furthermore, we have identified TRIM25 as a downstream regulatory target of CTSGDP-13. The expression of TRIM25 is significantly upregulated in BC, and its inhibition of ferroptosis promotes BC progression. Mechanistic studies have shown that CTSGDP-13 promotes the ubiquitination and subsequent degradation of TRIM25 by disrupting its interaction with the deubiquitinase USP7. Further investigations indicate that CTSGDP-13 promotes ferroptosis in BC by regulating the USP7/TRIM25/KEAP1 axis. The elucidation of the functional mechanisms of natural CTSGDP-13 and TRIM25 holds promise in providing valuable therapeutic targets for BC diagnosis and treatment.

Methionine orchestrates the metabolism vulnerability in cisplatin resistant bladder cancer microenvironment.

Metabolism vulnerability of cisplatin resistance in BCa cells remains to be discovered, which we applied integrated multi-omics analysis to elucidate the metabolism related regulation mechanism in bladder cancer (BCa) microenvironment. Integrated multi-omics analysis of metabolomics and proteomics revealed that MAT2A regulated methionine metabolism contributes to cisplatin resistance in BCa cells. We further validated MAT2A and cancer stem cell markers were up-regulated and circARHGAP10 was down-regulated through the regulation of MAT2A protein stability in cisplatin resistant BCa cells. circARHGAP10 formed a complex with MAT2A and TRIM25 to accelerate the degradation of MAT2A through ubiquitin-proteasome pathway. Knockdown of MAT2A through overexpression of circARHGAP10 and restriction of methionine up-take was sufficient to overcome cisplatin resistance in vivo in immuno-deficiency model but not in immuno-competent model. Tumor-infiltrating CD8+ T cells characterized an exhausted phenotype in tumors with low methionine. High expression of SLC7A6 in BCa negatively correlated with expression of CD8. Synergistic inhibition of MAT2A and SLC7A6 could overcome cisplatin resistance in immuno-competent model in vivo. Cisplatin resistant BCa cells rely on methionine for survival and stem cell renewal. circARHGAP10/TRIM25/MAT2A regulation pathway plays an important role in cisplatin resistant BCa cells while circARHGAP10 and SLC7A6 should be evaluated as one of the therapeutic target of cisplatin resistant BCa.

Prevalence of tumour-infiltrating CD103+ cells identifies therapeutic-sensitive prostate cancer with poor clinical outcome.

BACKGROUND: The clinical significance and immune correlation of CD103+ cells in prostate cancer (PCa) remain explored. METHODS: In total, 1080 patients with PCa underwent radical prostatectomy from three cohorts were enrolled for retrospective analysis. Tumour microarrays were constructed and fresh tumour samples were analysed by flow cytometry. RESULTS: High CD103+ cell infiltration correlated with reduced biochemical recurrence (BCR)-free survival in PCa. Adjuvant hormone therapy (HT) prolonged the BCR-free survival for high-risk node-negative diseases with CD103+ cell abundance. CD103+ cell infiltration correlated with less cytotoxic expression and increased infiltration of CD8+ and CD4+ T cells, M1 macrophages and mast cells in PCa. Intratumoral CD8+ T cell was the predominant source of CD103, and the CD103+ subset of CD8+ T cells was featured with high IL-10, PD-1 and CTLA-4 expression. Tumour-infiltrating CD103+ CD8+ T cells exerted anti-tumour function when treated with HT ex vivo. DISCUSSION: CD103+ cell infiltration predicted BCR-free survival and response to adjuvant HT in PCa. CD103+ cell infiltration correlated with an enriched but immune-evasive immune landscape. The study supported a model that CD103 expression conferred negative prognostic impact and immunosuppressive function to tumour-infiltrating CD8+ T cells, while the CD103+ CD8+ T cells exhibited a powerful anti-tumour immunity with response to HT.

CircDHRS3 inhibits prostate cancer cell proliferation and metastasis through the circDHRS3/miR-421/MEIS2 axis.

Prostate cancer is the most prevalent type of cancer among men worldwide. The importance of circular RNA (circRNA) in prostate cancer and its connection to malignancy has been steadily recognized. circRNA expression was obtained by circRNA sequencing of prostate cancer. circRNA and its function were further analysed. The results were verified by qRT-PCR, RIP assay, FISH, RNA pulldown, WB, CCK-8, colony formation assay and wound-healing assay. BALB/c Nude mice were used for xenograft hosts. Low expression of circDHRS3 was assessed in prostate cancer. Overexpression of circDHRS3 inhibited prostate cancer growth and migration in vitro. Additionally, miR-421 was shown to be the downstream target of circDHRS3, as shown by fluorescence in situ hybridization and dual-luciferase experiments. The rescue assay results for the PC3 and Du145 cell lines demonstrated that circDHRS3 inhibits prostate cancer cell lines' ability to proliferate and metastasize by modulating MEIS2 expression through the circDHRS3/miR-421/MEIS2 axis. In vivo investigations confirmed that the overexpression of circDHRS3 could inhibit both the lung and bone metastasis of prostate cancer cells. circDHRS3 has the potential to become a biomarker and a targeted therapeutic site for prostate cancer, particularly in the malignant stage. Our study indicates that circDHRS3 inhibits prostate cancer cell proliferation and metastasis through the circDHRS3/miR-421/MEIS2 axis.

Blood lipids, lipid-regulatory medications, and risk of bladder cancer: a Mendelian randomization study.

Background: The influences of blood lipids and lipid-regulatory medications on the risk of bladder cancer have long been suspected, and previous findings remain controversial. We aimed to assess the causality between blood lipids or lipid-regulatory medications and bladder cancer susceptibility by means of a comprehensive Mendelian Randomization (MR) study. Methods: Genetic proxies from genome-wide association studies (GWAS) of four blood lipid traits and lipid-lowering variants in genes encoding the targets of lipid-regulatory medications were employed. The largest ever GWAS data of blood lipids and bladder cancer involving up to 440,546 and 205,771 individuals of European ancestry were extracted from UK Biobank and FinnGen Project Round 6, respectively. A two-sample bidirectional MR study was performed using the inverse variance weighted as the main method. The heterogeneity, horizontal pleiotropy, MR Steiger, and leave-one-out analyses were also conducted as sensitivity tests. Results: There was indicative evidence that genetically predicted low-density lipoprotein cholesterol (LDL-C) affected bladder cancer susceptibility based on 146 single nucleotide polymorphisms (SNPs) with an odds ratio (OR) of 0.776 (95% confidence interval [CI] = 0.625-0.965, p = 0.022). However, this result became non-significant after two SNPs that possibly drove the effect were removed as demonstrated by leave-one-out analysis. The reversed MR analysis suggested that bladder cancer could not affect serum lipid levels. No causal relationship was found between the lipid-lowering effect of lipid-regulatory medications (fibrates, probucol, statins, ezetimibe, proprotein convertase subtilisin/kexin type 9 [PCSK9] inhibitors, and evinacumab) and the risk of bladder cancer. No heterogeneity or pleiotropy was found (all p > 0.05). Conclusion: This MR study revealed for the first time, using the most recent and comprehensive GWAS data to date, that genetically predicted total cholesterol (TC) and the lipid-lowering effect of lipid-regulatory medications had no causal association with bladder cancer susceptibility. We also verified claims from early studies that low-density lipoprotein cholesterol (HDL-C), LDL-C, and triglyceride (TG) are not related to bladder cancer susceptibility either. The current study indicated that lipid metabolism may not be as important in the tumorigenesis of bladder cancer as previously believed.

Silencing circFTO inhibits malignant phenotype through modulating DUSP4 expression in clear cell renal cell carcinoma.

Clear cell renal cell carcinoma (ccRCC) is the most diagnosed malignancy in kidney. Studies on the role of circular RNAs in kidney cancer are increasing. In this study, we employed high throughput sequencing and tissue micro array to detect and verify one of the key circular RNAs, circFTO, in ccRCC. The effect of circFTO on the proliferation and invasiveness of ccRCC cells and the corresponding mechanism were studied both in vitro and in vivo via multiple methods. We confirmed that circFTO was up regulated in ccRCC and correlated with a more aggressive phenotype. The up regulated circFTO could sponge and block the function of miR-514b-3p, a reported tumor suppressor, and caused overexpression of DUSP4. DUSP4 was found to lead to KRAS/ERK pathway activation, increased epithelial-mesenchymal transition (EMT) and inhibition of autophagy in ccRCC cells, which in the end boosted the proliferation and invasiveness of ccRCC. We thus concluded that circFTO/miR-514b-3p/DUSP4 axis may play an important role in ccRCC development and could be a potential biomarker and therapeutic target.

The potential mechanism of Longsheyangquan Decoction on the treatment of bladder cancer: Systemic network pharmacology and molecular docking.

Our goal was to explore the bioactive constituents of Longsheyangquan (LSYQ) Decoction and elucidate its mechanisms on the treatment of bladder cancer (BCa). A total of 38 compounds were selected based on their pharmacokinetic properties in three large traditional Chinese medicine (TCM) databases. 654 putative targets of LSYQ Decoction were predicted using a structure-based, reverse-docking algorithm online, of which 343 overlapped with BCa-related protein-coding genes. The protein-protein interaction (PPI) network was constructed to perform module analysis for further Gene Ontology (GO) annotations and Kyoto Encyclopedia Genes and Genomes (KEGG) pathway enrichment analysis, which identified CDK2, EGFR, MMP9 and PTGS2 as hub targets. The TCM-compound-target network and compound-target-pathway network together revealed that quercetin, diosmetin, enhydrin and luteolin were the main components of LSYQ Decoction. Finally, molecular docking showed the affinity between the key compounds and the hub target proteins to verify the accuracy of drug target prediction in the first place. The present study deciphered the core components and targets of LSYQ Decoction on the treatment of BCa in a comprehensive systemic pharmacological manner.

Identification and validation of a poor clinical outcome subtype of primary prostate cancer with Midkine abundance.

Recent studies identified Midkine (MDK) as playing a key role in immune regulation. In this study, we aimed to discover the clinical significance and translational relevance in prostate cancer (PCa). We retrospectively analyzed 759 PCa patients who underwent radical prostatectomy from Huashan Hospital, Fudan University (training cohort, n = 369) and Chinese Prostate Cancer Consortium (validation cohort, n = 390). A total of 325 PCa patients from The Cancer Genome Atlas (TCGA) database (external cohort) were analyzed for exploration. Immune landscape and antitumor immunity were assessed through immunohistochemistry and flow cytometry. Patient-derived explant culture system was applied for evaluating the targeting potential of MDK. We found that intratumoral MDK expression correlated with PCa progression, which indicated an unfavorable biochemical recurrence (BCR)-free survival for postoperative PCa patients. Addition of MDK expression to the postoperative risk assessment tool CAPRA-S could improve its prognostic value. Tumors with MDK abundance characterized the tumor-infiltrating CD8+ T cells with less cytotoxicity production and increased immune checkpoint expression, which were accompanied by enriched immunosuppressive contexture. Moreover, MDK inhibition could reactivate CD8+ T cell antitumor immunity. MDK mRNA expression negatively correlated with androgen receptor activity signature and positively associated with radiotherapy-related signature. In conclusion, intratumoral MDK expression could serve as an independent prognosticator for BCR in postoperative PCa patients. MDK expression impaired the antitumor function of CD8+ T cells through orchestrating an immunoevasive microenvironment, which could be reversed by MDK inhibition. Moreover, tumors with MDK enrichment possessed potential sensitivity to postoperative radiotherapy while resistance to adjuvant hormonal therapy of PCa. MDK could be considered as a potential therapeutic target for PCa.

Circ-AFAP1 promote clear cell renal cell carcinoma growth and angiogenesis by the Circ-AFAP1/miR-374b-3p/VEGFA signaling axis.

Clear cell renal cell carcinoma (ccRCC) is one of the most common urogenital tumors with high mortality. Circular RNA (circRNA), as an emerging endogenous RNA, has been proved to play a crucial role in the clear cell renal cell carcinoma (ccRCC) progression. In this study, we obtained circAFAP1 upregulated in ccRCC by high-sequencing and verified by qRT-PCR in several renal cancer cell lines. In situ hybridization (ISH) assays and Kaplan-Meier plot showed a higher level of circAFAP1 was linked to shorter overall survival. Moreover, CCK8, colony formation, and EdU experiments showed circAFAP1 promoted ccRCC growth while tube formation displayed circAFAP1 contributed to ccRCC angiogenesis. We predicted the downstream miR-374b-3p and VEGFA by bioinformatic analysis and validated further by qRT-PCR, RNA pull-down, RIP, and dual-luciferase. Downregulation miR-374b-3p or overexpression VEGFA could restore proliferation, vascular formation after circAFAP1 silencing. Consistently with the results in vitro, silencing circAFAP1 suppressed ccRCC growth in vivo. In conclusion, the circAFAP1/miR-374b-3p/VEGFA axis played a critical role in the progression and development of ccRCC which might be novel biological marks and therapeutical targets.

Exosome-derived circTRPS1 promotes malignant phenotype and CD8+ T cell exhaustion in bladder cancer microenvironments.

Circular RNAs (circRNAs) play critical roles in different diseases. Exosomes are important intermediates of intercellular communication. While both have been widely reported in cancers, exosome-derived circRNAs are rarely studied. In this work, we identified the differently expressed circRNAs in bladder cancer (BCa) tissue and exosomes through high-throughput sequencing. RNA pull-down, RNA immunoprecipitation, and luciferase reporter assays were used to investigate the interactions between specific circRNAs, microRNAs (miRNAs), and mRNAs. Wound-healing, Transwell, Cell Counting Kit-8 (CCK8), and colony-formation assays were used to study the biological roles in vitro. Metabolomics were used to explore the mechanism of how specific circRNAs influenced BCa cell behavior. Flow cytometry was used to study how specific circRNAs affected the function of CD8+ T cells in tumor microenvironments. We identified that exosome-derived hsa_circ_0085361 (circTRPS1) was correlated with aggressive phenotypes of BCa cells via sponging miR-141-3p. Metabolomics and RNA sequencing (RNA-seq) identified GLS1-mediated glutamine metabolism was involved in circTRPS1-mediated alterations. Exosomes derived from circTRPS1 knocked down BCa cells, prevented CD8+ T cells from exhaustion, and repressed the malignant phenotype of BCa cells. In conclusion, exosome-derived circTRPS1 from BCa cells can modulate the intracellular reactive oxygen species (ROS) balance and CD8+ T cell exhaustion via the circTRPS1/miR141-3p/GLS1 axis. Our work may provide a potential biomarker and therapeutic target for BCa.

DNA Methylation Modification Map to Predict Tumor Molecular Subtypes and Efficacy of Immunotherapy in Bladder Cancer.

Background: Considering the heterogeneity and complexity of epigenetic regulation in bladder cancer, the underlying mechanisms of global DNA methylation modification in the immune microenvironment must be investigated to predict the prognosis outcomes and clinical response to immunotherapy. Methods: We systematically assessed the DNA methylation modes of 985 integrated bladder cancer samples with the unsupervised clustering algorithm. Subsequently, these DNA methylation modes were analyzed for their correlations with features of the immune microenvironment. The principal analysis algorithm was performed to calculate the DMRscores of each samples for qualification analysis. Findings: Three DNA methylation modes were revealed among 985 bladder cancer samples, and these modes are related to diverse clinical outcomes and several immune microenvironment phenotypes, e.g., immune-desert, immune-inflamed, and immune-excluded ones. Then patients were classified into high- and low-DMRscore subgroups according to the DMRscore, which was calculated based on the expression of DNA methylation related genes (DMRGs). Patients with the low-DMRscore subgroup presented a prominent survival advantage that was significantly correlated to the immune-inflamed phenotype. Further analysis revealed that patients with low DMRscores exhibited less TP53 wild mutation, lower cancer stage and molecular subtypes were mainly papillary subtypes. In addition, an independent immunotherapy cohort confirmed that DMRscore could serve as a signature to predict prognosis outcomes and immune responses. Conclusion: Global DNA methylation modes can be used to predict the immunophenotypes, aggressiveness, and immune responses of bladder cancer. DNA methylation status assessments will strengthen our insights into the features of the immune microenvironment and promote the development of more effective treatment strategies.

Radiogenomics Map Reveals the Landscape of m6A Methylation Modification Pattern in Bladder Cancer.

We aimed to develop a noninvasive radiomics approach to reveal the m6A methylation status and predict survival outcomes and therapeutic responses in patients. A total of 25 m6A regulators were selected for further analysis, we confirmed that expression level and genomic mutations rate of m6A regulators were significantly different between cancer and normal tissues. Besides, we constructed methylation modification models and explored the immune infiltration and biological pathway alteration among different models. The m6A subtypes identified in this study can effectively predict the clinical outcome of bladder cancer (including m6AClusters, geneClusters, and m6Ascore models). In addition, we observed that immune response markers such as PD1 and CTLA4 were significantly corelated with the m6Ascore. Subsequently, a total of 98 obtained digital images were processed to capture the image signature and construct image prediction models based on the m6Ascore classification using a radiomics algorithm. We constructed seven signature radiogenomics models to reveal the m6A methylation status, and the model achieved an area under curve (AUC) degree of 0.887 and 0.762 for the training and test datasets, respectively. The presented radiogenomics models, a noninvasive prediction approach that combined the radiomics signatures and genomics characteristics, displayed satisfactory effective performance for predicting survival outcomes and therapeutic responses of patients. In the future, more interdisciplinary fields concerning the combination of medicine and electronics remains to be explored.

Calculated identification of mutator-derived lncRNA signatures of genomic instability to predict the clinical outcome of muscle-invasive bladder cancer.

BACKGROUND: Muscle-invasive bladder cancer (MIBC) is one of the most important type of bladder cancer, with a high morbidity and mortality rate. Studies have found that long non-coding RNA (lncRNA) plays a key role in maintaining genomic instability. However, Identification of lncRNAs related to genomic instability (GIlncRNAs) and their clinical significance in cancers have not been extensively studied yet. METHODS: Here, we downloaded the lncRNA expression profiles, somatic mutation profiles and clinical related data in MIBC patients from The Cancer Genome Atlas (TCGA) database. A lncRNA computational framework was used to find differentially expressed GIlncRNAs. Multivariate Cox regression analysis was used to construct a genomic instability-related lncRNA signature (GIlncSig). Univariate and multivariate Cox analyses were used to assess the independent prognostic for the GIlncSig and other key clinical factors. RESULTS: We found 43 differentially expressed GIlncRNAs and constructed the GIlncSig with 6 GIlncRNAs in the training cohort. The patients were divided into two risk groups. The overall survival of patients in the high-risk group was lower than that in the low-risk group (P < 0.001), which were further verified in the testing cohort and the entire TCGA cohort. Univariate and multivariate Cox regression showed that the GIlncSig was an independent prognostic factor. In addition, the GIlncSig correlated with the genomic mutation rate of MIBC, indicating its potential as a measure of the degree of genomic instability. The GIlncSig was able to divide FGFR3 wild- and mutant-type patients into two risk groups, and effectively enhanced the prediction effect. CONCLUSION: Our study introduced an important reference for further research on the role of GIlncRNAs, and provided prognostic indicators and potential biological therapy targets for MIBC.